Downhole acid injection to stimulate formation production

Abstract

A method for performing an acid stimulation operation using a downhole tool includes conveying the downhole tool in a borehole that is formed in a subsurface formation. The downhole tool includes a chamber to store stimulation fluid comprising a stimulation acid. The downhole tool includes a fluid injector that is fluidly coupled to an output of the chamber via a flow line of the downhole tool. The method includes coating the flow line with an acid resistant fluid. The method includes injecting, from the fluid injector via the flow line, the stimulation fluid into the subsurface formation that is released through the output of the chamber.

What is claimed is: 
     
       1. A method comprising:
 conveying a downhole tool in a borehole that is formed in a subsurface formation, the downhole tool having a chamber to store a pre-packaged acid-resistant container containing stimulation fluid comprising a stimulation acid, wherein the downhole tool comprises a fluid injector that is fluidly coupled to an output of the chamber via a flow line of the downhole tool; 
 coating the flow line with an acid resistant fluid; and 
 injecting, from the fluid injector via the flow line, the stimulation fluid into the subsurface formation that is released through the output of the chamber. 
 
     
     
       2. The method of  claim 1 , wherein injecting the stimulation fluid into the subsurface formation comprises injecting, after coating the flow line, the stimulation fluid into the subsurface formation. 
     
     
       3. The method of  claim 2 , further comprising:
 flowing an acid neutralizing fluid into the flow line after the injecting of the stimulation fluid. 
 
     
     
       4. The method of  claim 3 , further comprising:
 drilling, using a drill string through which a drilling mud flows and that includes the downhole tool, wherein the acid neutralizing fluid comprises the drilling mud. 
 
     
     
       5. The method of  claim 2 , wherein the chamber comprises a liner that is acid resistant and that is to store the stimulation fluid. 
     
     
       6. The method of  claim 2 , wherein the stimulation fluid comprises an acid resistant fluid. 
     
     
       7. The method of  claim 2 , wherein coating the flow line comprises releasing the acid resistant fluid from a coating container in the downhole tool after the downhole tool is conveyed downhole. 
     
     
       8. A downhole tool comprising:
 a chamber to store a pre-packaged acid-resistant container that includes a stimulation fluid comprising a stimulation acid; 
 a fluid injector; and 
 a flow line that fluidly couples an output of the chamber to the fluid injector, wherein the flow line is to be coated with an acid resistant fluid prior to the stimulation fluid being injected from the fluid injector, via the flow line, and out into a subsurface formation that is surrounding a borehole in which the downhole tool is positioned. 
 
     
     
       9. The downhole tool of  claim 8 , wherein an acid neutralizing fluid is to flow through the flow line after the stimulation fluid is injected out into the subsurface formation. 
     
     
       10. The downhole tool of  claim 9 , wherein the acid neutralizing fluid is to flow through the chamber after the stimulation fluid is injected out into the subsurface formation. 
     
     
       11. The downhole tool of  claim 9 ,
 wherein the downhole tool is part of a drill string having a drill bit to drill the borehole and through which a drilling mud flows, and 
 wherein the acid neutralizing fluid comprises the drilling mud. 
 
     
     
       12. The downhole tool of  claim 8 , wherein the chamber comprises a liner that is acid resistant and that is store the stimulation fluid. 
     
     
       13. The downhole tool of  claim 8 , further comprising:
 a coating container fluidly coupled to the flow line, wherein the coating container is to store the acid resistant fluid, wherein the acid resistant fluid is to be released from the coating container to coat the flow line after the downhole tool is in the borehole. 
 
     
     
       14. The downhole tool of  claim 8 , wherein the borehole is located at a well site for hydrocarbon recovery from the subsurface formation, wherein the flow line is to be coated with the acid resistant fluid at the well site prior to the downhole tool being positioned in the borehole. 
     
     
       15. The downhole tool of  claim 8 , wherein the stimulation fluid comprises an acid resistant fluid. 
     
     
       16. A downhole tool comprising:
 a chamber to store a pre-packaged acid-resistant container containing stimulation fluid comprising a stimulation acid and an acid resistant fluid; 
 a fluid injector; and 
 a flow line that fluidly couples an output of the chamber to the fluid injector, wherein the stimulation fluid is to be released from the chamber after the downhole tool is positioned in a borehole, and wherein the fluid is to be injected from the fluid injector, via the flow line, and out into a subsurface formation that is surrounding the borehole. 
 
     
     
       17. The downhole tool of  claim 16 , wherein an acid neutralizing fluid is to flow through the flow line after the stimulation fluid is injected out into the subsurface formation. 
     
     
       18. The downhole tool of  claim 17 , wherein the acid neutralizing fluid is to flow through the chamber after the stimulation fluid is injected out into the subsurface formation. 
     
     
       19. The downhole tool of  claim 18 ,
 wherein the downhole tool is part of a drill string having a drill bit to drill the borehole and through which a drilling mud flows, and 
 wherein the acid neutralizing fluid comprises the drilling mud. 
 
     
     
       20. The downhole tool of  claim 17 , wherein the chamber comprises a liner that is acid resistant and that is store the stimulation fluid.